1. Field of Invention
The present invention relates to telecommunications and, more particularly, to a hands-free teleconferencing apparatus and method that enable multiple people to participate in a wireless telephone call.
2. Description of Related Art
Current wireless telephones have provisions for the use of hands-free devices that allow the wireless telephone to be used without having to hold the wireless telephone next to user's ear. Current hands-free devices vary from what are commonly called earbuds to various types of headsets. A typical earbud includes an electrical cable having an acoustic transducer on one end, a connector on the other for connecting the earbud to a wireless telephone, and a microphone embedded in the cable between the wireless telephone and the acoustic transducer near the user's mouth. The acoustic transducer functions as a speaker and is typically designed to be inserted into the user's ear. The microphone of the earbud typically is located either near the user's mouth or near the user's ear. In some designs, the microphone is located at the end of a “boom” bracket near the user's mouth.
The connector attached to the end of the cable for connecting the earbud to a wireless telephone is often a standard 2.5 millimeter (mm) connector designed to be inserted into a standard 2.5 mm jack in the housing of the wireless telephone. Some earbud connector designs are not industry standards, but rather, are manufacturer-specific. For example, some connectors are designed to interface with the manufacturer-specific accessory interface of a wireless telephone rather than with a standard 2.5 mm jack.
In many designs, when the connector of the earbud is connected to the telephone, the telephone senses an impedance change that causes the telephone to switch from using the internal earpiece and microphone of the telephone to using the microphone and acoustic transducer of the earbud. Connection of the earbud to the wireless telephone disables the internal earpiece and microphone of the telephone and enables the microphone and acoustic transducer of the earbud.
Some earbuds have a call acceptance/termination switch connected to the earbud cable between the acoustic transducer and the connector. The user momentarily closes the switch to accept an incoming call and then closes the switch again to terminate the call. FIG. 1 illustrates a block diagram of such an earbud device. The earbud device 1 comprises a cable 2 having an acoustic transducer 3 on one end that functions as a speaker and a 2.5 mm connector 4 on the other end for connection with a 2.5 mm jack of a wireless telephone (not shown). A microphone 5 and a switch 6 are connected to the cable 1 at locations between the acoustic transducer 3 and the connector 4.
Some earbud designs include a headset that holds the acoustic transducer against the user's ear by some type of holding mechanism. Such headsets usually include some type of boom for holding the microphone near the user's mouth.
A design intended for use by the hearing impaired community utilizes a magnetic loopset to magnetically couple the acoustic energy from the loopset to hearing aid telecoils of the user's hearing aid.
Although each of the hands-free communications devices described above provides a hands-free environment in which a user is able to participate in wireless telephone calls without having to hold the telephone next to the user's ear, none of the designs enable multiple users to simultaneously participate in a wireless telephone call in a hands-free teleconferencing environment. With the ever-increasing use of wireless telephones, a need exists for a hands-free teleconferencing device that enables multiple users to participate in the same telephone call in a hands-free teleconferencing environment using a single wireless telephone.